Phantastes

George MacDonald's Phantastes, first published in 1858, is a classic text that influenced C. S Lewis, J.R.R. Tolkien and others in the succeeding 20th century.

Here's another brief quotation from this novel :

As through the hard rock go the branching silver veins; as into the solid land run the creeks and gulfs from the unresting sea; as the lights and influences of the upper worlds sink silently through the earth's atmosphere; so doth Faerie invade the world of men, and sometimes startle the common eye with an association as of cause and effect, when between the two no connecting links can be traced.